1. Technical Field
The present invention relates to a method of manufacturing a liquid vessel for supplying a predetermined liquid to a liquid consuming apparatus such as a liquid ejecting head for discharging a small amount of liquid drops.
2. Related Art
A liquid ejecting head of a commercial recording apparatus requiring ultra-high quality printing, such as a printing apparatus or a micro dispenser, receives liquid discharged from a liquid vessel. However, when the liquid ejecting head operates in a state in which the liquid is not supplied, a so-called idle operation is performed and the liquid ejecting head may be damaged. Accordingly, in order to prevent this kind of damage, a residual amount of liquid in the vessel should always be monitored.
Accordingly, a variety of recording apparatuses have been suggested in which a device for detecting a residual amount of ink is included in a liquid vessel such as an ink cartridge. One example of an ink cartridge including a liquid residual amount detection device comprises an ink cartridge including a liquid containing body for discharging stored liquid through a discharge port and the liquid residual amount detection device by pressurization, where the liquid residual amount detection device is connected to the liquid containing body. Here, the liquid residual amount detection device includes a piezoelectric element for applying vibration to a flow path whose one end is connected to the discharge port of the liquid containing body and whose other end is connected to the liquid lead-out portion for supplying liquid to the outside. A residual amount of liquid in the liquid containing body is detected by detecting a variation in acoustic impedance when the vibration is applied by the piezoelectric element.
However, even in the ink cartridge including a liquid residual amount detection device, if air bubbles remain in the liquid containing body or the flow path of the liquid residual amount detection device when the ink cartridge is mounted in a recording apparatus, the remaining air bubbles are supplied to the recording apparatus, thus causing a problem such as an idle operation of a recording head.
Accordingly, when such an ink cartridge is manufactured, an advanced charging technology for charging ink such that air bubbles do not remain in the liquid containing body or the flow path in the liquid residual amount detection device is needed.
Under such circumstances, as a method of charging the ink into the ink cartridge, the liquid residual amount detection device is connected to an empty liquid containing body in advance, an external suction device is connected to the liquid lead-out portion, and deaeration is performed with respect to the liquid residual amount detection device and the liquid containing body by negative pressure suction with the suction device. Thereafter, instead of the suction device, a method was suggested of connecting an ink supply path from the ink charging portion to the liquid lead-out portion and pressurizing and charging the ink into the liquid residual amount detection device and the liquid containing body (see, for example, JP-A-2005-96469).
However, in the method of charging the ink into the ink cartridge, equipment is required for rapidly connecting and switching the suction device for performing deaeration with respect to the empty liquid residual amount detection device and the liquid containing body through the liquid lead-out portion, while a deaeration state is maintained by the suction device. Thus, equipment necessary for charging the ink becomes complicated or equipment cost is increased.
A deaeration degree of the suction device is apt to be uneven due to flexibility of the liquid containing body or the structure of the flow path of the liquid residual amount detection device. When the connection to the liquid lead-out portion is switched from the suction device to the ink charging device, the deaeration degree may be reduced, although a variation thereof is small. Accordingly, it is difficult to stably produce a product having a predetermined deaeration degree.
When a load due to a suction negative pressure is applied to a sensor in the liquid residual amount detection device for a long time, such as during the deaeration process either before charging the ink or before applying a positive pressure at the time of charging the ink, the sensor in the liquid residual amount detection device may be damaged.